At the bottom of Britain's deepest mine, scientists are putting their finishing touches to a device that could solve one of astronomy's most baffling mysteries: the location of the universe's missing matter. If they succeed, the group will snatch some of the glory from one of the most prestigious scientific projects undertaken in recent years: the £3.5bn Large Hadron Collider (LHC), which is to be opened officially in Geneva this week.

Both machines are attempting to pinpoint mysterious particles, called dark matter, which is thought to permeate the universe. The LHC is the favourite candidate to achieve this goal, but is unlikely to complete the task for at least two years. The Boulby project, based in a £2m underground laboratory in Cleveland, could succeed in half that time.

"We have been astounded how well Zeplin-3 has performed during trials," said project scientist Alexander Murphy. "We are now going to carry out upgrades and will then run the machine for several months. With a bit of luck, we could pinpoint dark matter in a year."

Scientists know the universe contains more matter than can be detected through their telescopes because they can see that galaxies hold together in clusters when they should be flying apart. Extra mass is generating increased gravity and holding these galaxies together, they conclude. This unseen mass is called dark matter and two different candidates have been proposed: one with the acronym Machos and the other called Wimps.

Macho is a massive astronomical halo object. These are huge objects – such as burnt-out stars – that cannot be seen directly but which could generate vast gravitational fields. But detailed astronomical surveys have failed to reveal even a hint of one.

This leaves wimps: weakly interacting massive particles. These are subatomic particles that only rarely interact with normal matter and scientists now believe they account for dark matter though they have not yet observed them. One task for the LHC collider in Geneva is to make wimps from other particles to demonstrate their existence.

But the Zeplin-3 project – set up by Edinburgh University and Imperial College London researchers with US and Russian collaboration – could get there first. Their device is housed at the bottom of Boulby mine where millions of tonnes of potash, for fertiliser, and salt, for gritting roads, is extracted every year. A sprawling labyrinth of galleries, covering hundreds of miles, has been carved out here, more than three thousand feet underground.

In one side gallery, scientists have created their dark matter laboratory. "Cosmic rays – which constantly batter Earth's surface and pass through our bodies – cannot pass through the half-mile of rock above our heads," said fellow Boulby researcher Sean Paling. "We are protected from particle bombardment."

And without other particles battering their instruments, scientists hope to pinpoint wimps when they make their very rare interactions with normal matter. To do this, they have filled a large tank with the inert gas xenon and fitted it with detectors that can spot the flashes of light that should be produced when wimps occasionally strike xenon atoms. During tests run earlier this year, Zeplin-3 operated flawlessly, raising hopes that, when in full operation over the next nine months, it will spot occasional wimp interactions. "It is an outside chance, but after our trials have gone so well it is a now a very good outside chance, we think," said Murphy.

Success would be an enormous coup for the group: the contrast between Geneva's LHC machine and Boulby could not be more marked. The former has taken 10 years to build and is the size of London Underground's Circle Line. Zeplin-3 is the size of a large cupboard but still has to be kept scrupulously clean even though it has been erected inside a working potash pit.

"It is a very different world down here," said Paling. "You have to put on mining gear, fulfil careful safety requirements and take great care not to get lost in all the different galleries. It's not like that in Geneva."